/**
 * Copyright (C) 2012 Oleg Anastassov <o.anastasov@gmail.com>
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package kz.kstu.ent.business.server.context;

import kz.kstu.ent.business.server.api.Service;

import java.util.HashMap;
import java.util.Map;


/**
 * @author Oleg Anastassov
 */
public abstract class AbstractServerContextManager {

    private static final String API_PACKAGE_NAME = "api";
    private static final String IMPL_PACKAGE_NAME = "impl";
    private static final String IMPL_CLASS_POSTFIX = "Impl";
    private static final Map<String, Service> SERVICE_CACHE = new HashMap<String, Service>();

    private ServerContext serverContext;

    protected <T extends Service> T getService(Class<T> serviceInterface) {
        String serviceName = serviceInterface.getSimpleName();
        T service;
        if (SERVICE_CACHE.containsKey(serviceName)) {
            service = (T) SERVICE_CACHE.get(serviceName);
        } else {
            String className = serviceInterface.getName().replace(API_PACKAGE_NAME, IMPL_PACKAGE_NAME) + IMPL_CLASS_POSTFIX;
            try {
                Class<T> serviceClass = (Class<T>) Class.forName(className);
                service = serviceClass.newInstance();
                service.setServerContext(serverContext);
                SERVICE_CACHE.put(serviceName, service);
            } catch (ClassNotFoundException e) {
                throw new IllegalArgumentException("Error during getting service: " + serviceInterface.getSimpleName(), e);
            } catch (InstantiationException e) {
                throw new IllegalArgumentException("Error during getting instance of service: " + serviceInterface.getSimpleName(), e);
            } catch (IllegalAccessException e) {
                throw new IllegalArgumentException("Error during getting instance of service: " + serviceInterface.getSimpleName(), e);
            }
        }
        return service;
    }

    public void setServerContext(ServerContext serverContext) {
        this.serverContext = serverContext;
    }

    protected ServerContext getServerContext() {
        return serverContext;
    }
}
